Fine-grading machine for highway construction



Dec. 20, 1927. 1,653,333

I R. D. BAKER FINE GRADING MACHINE FOR HIGHWAY CONSTRUCTION Filed Dec; 5. 1924 4 SheetsSheet 1 D3 fmfeniz;

ditto? My Dec. 20, 1927. 1,653,333

I R. D. BAKER FINE GRADING MACHINE FOR HIGHWAY CONSTRUCTION Filed Dec. 5. 1924 4 Sheets-Sheet 2 R. D. BAKER FINE GRADING MACHINE FOR HIGHWAY CONSTRUCTION Dec. 20, 1927.

Filed Dec. 3. 1924 4 Sheets-Sheet 3 mm i NH" II i Dec'. 20, 1927,

R. D. BAKER FINE GRADING MACHINE FOR HIGHWAY CONSTRUCTION Filed Dec. 5. 1924 4 Sheets-Sheet 4 o o w \m U Q Q 0 271K, 5 e a HM w M d r w r llll O O N 9 I a Wi 2 a Q m 1 1 T P 2 2 w P Patented Dec. 20, 1927.

PATENT OFFICE.

ROBERT-D. BAKER, OF BIRMINGHAM, MICHIGAN.

FINE-GRADING MACHINE FOR HIGHWAY CONSTRUCTION.

Application filedDecember 3, 1924. Serial No. 753,560.

I This invention relates to subgrading ma: chines particularly adapted .for preparing the foundation or subsurface of paved streets, roads and the like, and has for its object to provide a simple and efficient machine or device of-this character.

In the construction ofconcrete and other highways, the modern practice is to first rough-grade the subsurface to within about two inches above the ultimate or fine-grade upon which the pavement is to be laid. The rough-grading is accomplished by means of plows and road-scraping machines. Stakes are then driven at intervals in proper position relative to the side edges of the ultimate pavement for the support of the chalk lines affording the guiding means determining pavement crown and width.

Following the staking and drawing of these guide lines, the trenching for the siderails or forms is effected, this being ordinarily followedby laying the said side-rails, the latter being, in some instances, employed to support a fine-grading. machine or device and thereafter to support a surfacing machine, there being several of the latter in very general use. i The most commonly used paving material of the present day is concrete and the al- .most universal type of concrete pavement laid outside of city streets is that which is known as a single course pavement, as distinguished from the two-course type consistlng of a sublaycr and a finishing layer of paving materials Following rough-grading and laying of side-rails, and frequently, following fine grading, the concrete mixer of the boom and bucket caterpillar tractor type, is run onto the sub-surface, either rough or fine, and moves in advance of the pavement as the latter is laid between the side forms. Where the mixer is run on the rough grade, the fine grading is usually effected manually by shovels between the mixer and the point of last deposit of the concrete. Thisis, in fact, the most common procedure because of the fact that the mixer is supplied with its charges of ingredients by means of trucks traveling upon the 'subgrade from the stock-sheds and heaps some distance beyond the point of operationof the mixer.

These trucks produce ruts and mitigate against fine-grading except between the mixer and point of deposit of batches.

In many instances, however, the hauling of ingredients is effected over a narrow gauge railway disposed at one side of the roadway beyond the stake-line or laid in the middle of the roadway. This means of transportation obviates rutting and permits fine-grading far ahead of the point of immediate operation, the expense of this railway equipment being such that comparatively few road-building contractors have it.

In some instances planks are laid upon advance fine grades for supply motor-trucks to run upon to prevent rutting.

My present invention has for. its object to provide a fine-grading machine which may be embodied as a motor-actuated or as a manually operable machine for effecting long stretches of fine-grading in advance of pavement laying where the mode of supplying the concrete mixer issuch as to obviate rutting and cutting up of the fine several passages removing surplus earth by courses or layers and being necessary under some conditions. A further object of such adjustment is to permit the carriage to travel upon the high side rails of the form and to also permit temporary use of far lower rail road rails temporarily laid in the trenching for the side-rails where fine grading proceeds far in advance of mixer operations.

Other objects of the invention will appear in or from the following specification.

Subgrading machines embodying the invention are fully' illustrated in the accompanying drawings, wherein:

Fig. 1 is a top plan view of a motor propelled and motor actuated subgrading machine constructed in accordance with my invention.

Fig. 2 is a front elevation of the same. Fig. 3 is a vertical longitudinal section of the same on the line 3-3 of Fig. 1. v

Fig. 4 is a fragmentary vertical transverse section of the same on the line 44 of Fig. 1.

ill

Fig. 5 is a detail section of the same on the line 55 of Fig. 3.

Fig. 6 is a top plan view of a manually operable subgrader constructed in accordance with the invention.

Fig. 7 is a front elevation of the same.

Figs. 8 and 9 are vertical longitudinal sections on the line 88 of Fig. 6 showing the relatively movable parts thereof in respectively different positions.

Fig. 10 is a fragmentary detail section on the line 1010 of Fig. 8.

Fig. 11 is a diagrammatic view illustrative of the nature of the fine-grade surface produced by the machines illustrated.

The machine comprises a suitable carriage which may be convenientlyconstructed from commerical structural steel units of types and sizes adapted to the purpose. The said carriage comprises the side-frames or trucks 1 each equipped with a pair of flanged wheels 2 adapted to run on rails 3 which may be of the standard type of railroad-rail or of the type which is commonly used to constitute the side walls of the form for receiving the plastic concrete of the pavement structure. The wheels 2 are preferably flanged along both edges and present inter-' mediate faces of considerably greater width than the crowns of the rails 3 so as to avoid the necessity of too accurately. spacing the latter The rails are laid upon the flat bottoms of the trenches at each side of the road- Way which are dug after rough-grading has been completed, said trenches being at least as wide as the blade of the shovel used by the person digging the same and thus permitting some lateral displacement or adjustment of rails laid thereon Where the railroad-rails are employed, their use is temporary and precedes the more accurate laying of the side-rails of the pavement form (which are also known as side-forms) and the wide faces of the wheels obviate the accurate laying of said temporary rails to accommodate the carriage.

The said side-frames 1 are connected in fixed parallelrelation by means of a plurality of cross-beams 4, 5', 6, 7 and 8, said members 4 and 7 being connected to the ends of the side-frames or trucks between the upper and lower faces of the latter the element 6 being disposed between and on the same level as said elements 4 and 7, while the elements 5 and 6 are secured tothe lower faces of the side-frames or trucks-between the ends thereof. Further bracing elements may be employed as desired, it being understood that the details of construction of the frame may be changed and varied as engineering skill and practice dictate, it being particularly desirable to render said frame as light as possible with relation to the degree of inflexibility requisite to proper operation of the mechanism supported-thereby to insure proper performance of function by safid mechanism.

A further structural steel unit, such, as a heavy angle-iron 10 extends parallel with and contiguous to the element 5 of the frame and is secured at its ends to the side frames of trucks 1. On the lower face of the anglebar 10 there are mounted the bearings for a shaft 10 equipped with a plurality of eccentrics 10 which are operativel associated with the shovel element 11 whic consists of a steel plate substantially the same length as the saidangle bar 10 and which is of such width that, normally, its inclination from its upper to its front or cutting edge will approximate an angle of about thirty to forty 1 degrees to the horizontal plant of said hinged edge. The front or cutting edge of said blade or shovel-member 11 is preferably slightly serrated and is also bent or formed to correspond to the lateral contour of the fine-grade of the pavement foundation if the latter be other than perfectly plane. The said shovel element may be constructed of several parts, including suitable stiffening or reinforcing means such as the angle-bar 12 without departing from the invention, the latter being herein illustrated in. a simple .and more or less diagrammatic manner.

Between the upper and cutting edges of said shovel element 11, the latter is provided with a plurality of, preferably, rectangular openings 13 each of which is adapted to be closed by a suitable gate 14, said openings being suitably spaced from each other. All of the gates l4'are rigidly mounted on a rock-shaft 15 journalled in hearings on the nether face of the shovel element 11, for simultaneous operation of said gates 14, said shaft being equipped with a lever 17 at one end for rocking the same. A notched quadrant 18 disposed on the shovel 11 in engaging relation to the spring-held dog 19,

operable by means of the grip-lever 20 on said lever 17, serves to maintain the several series of gates 14 in either open or closed position.

Connected with the cutting edge-portion pivotally associated with the lower ends of the forked connecting rods 27 reciprocable by means of eccentrics on the shaft 28 extending parallel with and journalled in bearings carried by said frame element 6.

The shaft 28 is suitably operatively geared to the shaft 29 of the motor 30 which is conveniently mounted on one of the side frames 1, a clutch operable by the lever 31 being suitably interposed in said gearing for controlling the operation of said shaft 28. Said shaft 28 is geared to the shaft 10 by means of sprockets 28 and sprocketchain 28 for rotation of said shafts 10 and 28 in unison at, preferably equal speeds to thereby impart to the shovel element 1.1 a

compound motion whereby its cutting edge is reciprocated back and forth at the same time as it is raised and lowered, the eccentrics on said shafts being relatively (11S- posed to synchronize the respective move-.

ments in any desired relation to each other.

Depending from the carriage is the framing 32 supporting the bearings of the shafts or trunnions of the pulleys 33 over which a conveyor-belt 34'is trained, one of said pulleys being operatively geared to the motorshaft 29, the clutch operable by the lever 35 being interposed in the connection. This belt 33 is disposed mainly below the shovel 11 and is adapted to receive earth passing through the openings 13 in said shovel when the gates 14 are open. The said belt extends substantially from one side-frame or truck 1 to the other and travels in a direction to deliver earth carried thereby to the conveyor-belt 36 trained over pulleys 37 suitably rotatably mounted in the projecting frame-portion 38 of the carriage, said gearing being convenient-1y eX-' emplified by the worm 39 and worm-wheel 40. The latter is appropriately operatively associated also with wheels 2. A clutch operable by the lever 41 controls the travel of the carriage in the forward direction,

there being no reversing-gear illustrated or necessary inasmuch as reverse travel of the.

carriage is easily accomplished manually by the operators in attendance.

The shovel 11 is illustrated in Fig. 3 as disposed at its maximum elevation in the course of operations. It may be lowered to effect deeper cut by manual operation of the screw-shafts 22 which are reciprocated in unison with the slight'motions of the shovel as imparted thereto by the eccentrics on the shafts 28 and 10. As the carriage travels forward, these slight motions of the shovel serve to break up the earth at the same time that it is cut into and also assist in causing the loosened earth to move up the shovel and upon the angle-bar 10. When the gates 14 are open, a large part of the earth will pass through the same, it being very desirable that some thereof be available to operators in attendance to be shoveled back upon the fine-grade behind the machine to fillany hollows occurring therein, all earth accumulating on the shovel in excess of requirements for filling hollows, being manually moved to drop through the openings 13 or being shoveled to the opposite side of the roadway from that to which the conveyor-belts deliver the earth for filling voids at the said other side. The reciprocatory movement of the shovel also assists greatly in the removal of pebbles of considerable size sometimes encountered and to cause the shovel to pass over those of too large size to be liberated by the shovel. The latter possesses suflicient resiliency to resist permanent distortion due to collision with or riding over obstructions which it is incapable of dislodging. Such collision would cause the carriage to cease traveling while during the interval of riding over an obstruction the carriage would be lifted at least in part and be, to that extent, carried by the portion of the shovel resting on the obstruction. The operator would, obviously, quickly throw the levers 41 and 31, then manually reverse the travel of the carriage and remove the obstruction.

The structure of Figs. 1 to 5 inclusive is particularly intended and adapted for finegrading the earth foundation of the pavement where such work is practicable far in advance of the point of operation of the mixer, while that-shown in Figs. 6 to 10 inclusive is better adapted for piecemeal finegrading as above pointed out, and for long stretches of advance work when drawn by a suitable tractor or other means, its use in both kinds of work above noted, being, it is believed, far more economical than and superior to'that performed by hand labor and by any other machines now in general use.

' The structure of Figs. 6 to 10 includes the side-frames or trucks 42, wheels 43 and connecting frame elements 44, 45, 46 and 47 and some suitablebracing members 48, the anglebar 49, theshovel 50 hinged to the angle-bar 49, the screwshafts 51 having threaded engagement between their ends with the sleeves 52 pivotally mounted on the frameelement 47 andv the universal joint. connections 53 of the screw-shafts with the cutting edge portion of the shovel, the number and relative positions of the frame elements 44 to 47 inclusive being slightly different from the similar parts of the structure of Figs. 1 to 5 inclusive.

. The side frames 42 are split between their ends as shown at 54 to divide each thereof into two parts, one thereof indicatedv b reference character 42 and the other by re erence character 55, which are secured together by means of the hinges 56 mounted on their lower faces, the opposed ends of the iac frame element 46 which is supported upon the upper faces of the portions 42 of the sideframes in such position that the rollers 59 normally bear against the flanges 57. Each member 42 of the side-frames is equipped with a railing 62 disposed inwardly thereof so as to permit an operator to stand on said side-frame portion 42 and hold on to said railing while with one foot he successively depresses and raises the long end portion of the lever 58 as the carriage moves forward.

This relative pivotal movement of the two parts of the side frames as is illustrated by Figs. 8 and 9 and a substantially vertical reciprocatory movement of the cutting edge of the shovel. The earth piling up on the latter is shoveled to the sides of the roadway and into hollows and voids occurring in the fine grade by operators conveniently standing on the anglebar 49.

It will be obvious that the cut made by the shovel must of necessity produce a fine-grade which presents a minutely corrugated surface. In practice the cutting edge of the shovel is set so that in its lower position its lower edge lies in the predetermined gradeplane and in its higher position it is disposed above the same. The stroke of this edge will range from a minimum of about one-quarter of an inch to a maximum of possiblyv three quarters of an inch, depending upon the nature of the earth.

In the operation of the power actuated machine the reciprocatory' movements of the cutting edge of the shovel are so regulated as to'the number of said reciprocatory move ments per foot of travel of the carriage that the fine-grade surface produced presents a very smooth appearance to the naked eye, that is to say, to present a surface which reveals lateral ridges and depressions only upon very close inspection. As above point ed out, the reciprocatory stroke of the shovel is very limited and, generally, of a maximum far below the depth of the soil layer to be removed from above the fine-grade plane, the action of the cutting edge of the shovel being, under the influence of the compound movement above described, to substantially pulverize or break up into small fragments a thin layer of compacted earth disposed directly above the fine-grade plane and between the latter and the surface of the rough-grade, the surface earth to be removed being thus undermined and broken up into relatively small lumps. The roughgrade is first undermined by the shovel edge and thereafter, by further penetration of the latter and due to either the inclination of the upper surface of the shovel or to the slight up and down strokes of the latter, the earthcrust above the zone of undermining by the cutting edge, is raised and broken up and caused to mount or ride over the top rear edge of the shovel as the latter moves forward. Following passage of the machine, the surface is subjected to the action of a heavy roller which eliminates the corrugations and provides a perfectly smooth fine-grade.

In so far as undermining the layer of earth to be removed consists in effecting a pulverization or breaking up, as aforesaid, of a thin layer thereof immediately overlying the fine-grade plane, is concerned, the invention includes a seemingly entirely novel method as distinguished from past practices so far as the same are known to me.

In the case of the manually operable machine of Figs. 6 to 10, inclusive, as well as in the case of the power actuated machine, when only the up and down movement of the shovel edge is effected as in the manually operated device, the cutting edge of the shovel isset so that in its lowest position it is disposed slightly below the exact finegrade plane and, in fact, so that the latter lies midway between the limits of up and down reci-procatory or rocking movements of the cutting edge of the shovel thereby producing a slightly corrugate surface, the ridges and hollows of which are disposed substantially equal distances above and below the actual fine-grade plane. The mean length of the corrugations depends upon the number of reciprocatory strokes of the shovel edge per foot of travel of the carriage. In actual practice the speed of reciprocation of the shovel'edge isabout six up and six down strokes per foot vof travel of the machine and the'length of said stroke is approximately one-half inch, these move-' ments of the shovel edge being variable without departing from the invention.

removal in the case of the manually operable machine.

Expressed in terms of method the invention consists broadly in maintaining the shovel edge at all times below the surface eral direction while so maintained, and imparting to it during such travel a slight movement laterally of the general direction thereof.

It will be obvious, of course, that the accuracy of the fine-grade is dependent upon the accuracy with which the side rails of the form are laid and this, in turn, isdependent upon the accuracy of the trenching for the side rails. The machines as illustrated are intended for riding on side rails but may be designed for travel in the side rail trenches or their equivalent in instances where side rails are not employed. In many instances the side rails may be the crowns or gutters of curbing. i

In practice the up and down movements of the shovel edge causes the latter to dislodge rocks and pebbles of considerable size em bedded or partially embedded in the roadbed without undue strain or stress on the machine or shovel edge, this beingexceedingly advantageous.

Practice has demonstrated that the con ventional road scraper wherein the scraper blades are rigid with respect to the carriage, will remove or cut away only a very thin layer of compact earth in a single passage over the area to be fine-graded. Rough grading by means of plows leaves from one to six inches depth of compact earth crust to remain over the ultimate fine-grade plane, and in most instances all of this surplusage is removed by a single passage of the machine of this invention over said area. This is possible only by effecting the lateral moveare above the same, the depth'of the hollows measured from the tops of the ridges being epual to the stroke of reciprocation of the shovel-edge, said stroke being adjustable by connecting the rods 16 in various openings in the links 26 as shown in Figs. 3, 4: and 5 description to means for imparting sub.-

stantially vertical reciprocatory movements to the shovel edge, the invention comprehends the broad idea of slmultaneous moveuniforml ments in divers directions within the definition of the appended claims.

I claim as my invention:

1. A fine-grading machine including a wheeled frame adapted to be supported on rails disposed over opposite sides of the area to befine-graded, a shovel carried by said frame disposed at an incline to the plane of the ultimate fine grade with its cutting edge substantially in said plane, and means for imparting a slight reciprocatory movement to the cutting edge portion of said shovel successively during travel of said carriage for- Wardly along said railsto provide for successive elongated surface removing cuts transverse of an uneven road surface to grade it throu hout.

2. A ne-grading machine including a Wheeled frameladapted to'be supported on rails disposed upon opposite sides of the area to be fine-graded, a shovel carried by said frame disposed atan incline to the plane of the ultimate fine grade with its cutting edge substantially in said plane, and means for imparting a slight reciprocatory movement to the cutting edge portion of said shovel successively during travel of said carriage along said rails to provide for successive elongated surface removing cuts transverse of an uneven road surface to grade it uniformly throughout, and means for adjusting vertically the cutting edge portion of the shovel relative to the plane of support of the carriage.

3. A fine-grading machine including a wheeled frame adapted 'to be supported on rails disposed upon op osite sides ofthe area to be fine-graded, a s ovel carried by said frame disposed at an incline to the plane of the ultimate fine grade with its cutting edge substantially in said plane, and means for imparting a slight reciprocatory movement to the cutting edge portion of said shovel successively during travel of said carriage in the direction of pro'ection of the said cutting Ill?) edge portion of said shovel to provide for I successive elongated surface removing cuts transverse of an uneven road surface to grade it uniformly throughoutand means for adjusting the cutting edge portion of the shovel relative to the plane of support. of the carriage the said adjusting means being wholly independent of the means for imparting reciprocatory movement to said shovel.

4. A fine-grading machine including a wheeled carriage adapted to travel on rails disposed upon 0 posite sides of the area to be fine-graded, a s ovel carried by said frame and extending substantially the entire width of said area and having its cutting-edge disposed substantially in the plane of the said ultimate fine-grade, means for adjusting the elevation of'said cutting edge of said shovel relative to the plane of support of the wheeled carriage, a motor on the latter, manlat ually controlled gearing between said motor and the carriage, and manually controlled earing between the motor and the shovel or imparting to the latter a slight reciprocatory movement.

. 5. A fine-grading machine including a wheeled carriage adapted to travel on rails dis osed upon opposite sidesof the area to be lie-graded, a shovel carried bysaid frame and extending substantially the entire width of said area and having its cutting-edge disposed substantially in the plane of the ultimate fine-grade, means for adjusting the elevation of said cutting edge of said shovel relative to the plane of support of the wheeled carriage, a motor on the latter, manually controlled gearing between said motor and the carriage wheels for propelling the carriage, and manually controlled gearing between the motor and the shovel for imparting to the latter a slight reciprocatory movement, said shovel disposed at an incline for causing earth displaced thereby to move toward its upper edge, there being openings in said shovel through which a a part of the said earth may pass, conveying means disposed to receive the earth passing through said openings and deliver the same beyond the rail at one side of said area, and manually controlled gearing between said conve in means and said motor.

6. X ne-grading machine including a wheeled carriage adapted to travel on rails disposed upon opposite sides of the area to be fine-graded, an inclined shovel hinged to said frame and extending substantially the entire width of said area and having its cutting edge disposed substantially in the plane of the ultimate fine-grade, conveying means associated with said shovel, means for imparting a slight reciprocatory movement to said shovel during travel of said carriage, a motor on the latter, and manually controlled gearing between said motor, the carriage wheels, the conveying means and the said shovel for operating the same independently or in unison.

I 7. A fine-grading machine including a wheeled carriage adapted to travel on rails dis osed upon opposite sides of'the area to be ne-graded, a downwardly inclined shovel hinged at its top to said frame and extending substantially the entire width of said area and having its cutting-edge disposed substantially in the plane of the ultimate fine-grade, means for adjusting the elevation of said cutting edge of said shovel relative to the plane of support of the wheeled carriage, conveying means associated with said shovel, mechanism operatively associated with said shovel for imparting a slight reclprocatory movement thereto during travel of said carriage, a motor on the latter, and manually controlled gearing between said motor, the carriage wheels, the conveying means and the said mechanism for operating the same independently or in unison.

8. A fine-grading machine including a wheeled carnage adapted to travel on rails disposed upon opposite sides of the area to be fine-graded, a shovel carried by said frame and extending substantially the entire width of said area and having its cutting edge disposed substantially in the plane of the ultimate fine-grade, said shovel disposed at an incline adapted to cause earth displaced thereby to move over its surface, there being a plurality of openings in the shovel through which a part of said earth is adapted to pass, manually operable gates for closing said openings, conveying means disposed to receive the earth passing through said openings and carry the same beyond one of the said rails, mechanism for imparting reciprocatory motion to the shovel during travel of the carriage, a motor on the latter, and manually controlled gearing between said motor, the carriage wheels, the conveying meansand the said mechanism for operating the same independently or in unison. i

9. In a fine-grading machine, a carriage, an inclined pivotally supported shovel element, a motor with said carriage, and means associating said motor and shovel element for imparting to the latter a compound motion including a forward and a substantially vertical reci rocatory movement.

10. In a li ne-grading machine, a carriage, a motor and an inclined, pivotally supported shovel element operatively associated with said carriage and motor, and means included in said association for imparting to said shovel simultaneously a forward and back reciprocatory movement and an up and down rocking movement. 4

11. In a fine-grading machine, a carriage, a motor and an inclined, pivotally supported shovel element operatively associated with said carriage and motor, and means included in said association for imparting to said shovel simultaneously a forward and back reciprocatory movement and an up and down rocking movement and means for adjusting the extent of one of said movements.

12. In a machine of the kind specified, a

carriage, a permanently inclined, pivotally with the plane of the ultimate fine-grade of said area, a shovel blade operatively associated with said frame for rocking movement relative to the latter, a motor. carried by and operatively associated with said frame for propelling the latter and operatively associated with the shovel blade for rocking the latter to thereby impart to the cutting edge of the shovel blade a limited move ment lateral to the ultimate fine-"grade plane, manually operable means controlling the. association of the motor with said shovel blade, and manually operable means con-. trolling the propulsion of the carriage by said motor. l

14'. In a fine-grading machine, a carriage adapted for travel in a predetermined plane parallel with the plane of the ultimate finegrade, a motor on said carriage for effecting adapted for travel in a predetermined plane parallel with the plane of the ultimate linegrade, a motor on said carriage for effecting travel thereof, a shovel element on said carriage adjustable relatively thereto to dispose 3 its cutting edge in a plane substantially coincident with that of the ultimate fine-grade, gearing between the motor and the shovel element to reciprocate the cutting edge of the latter in a general direction lateral to the direction of travel of said carriage and 4 shovel element and with a stroke equal to a fraction of the rate of travel of said carriage per minute during such travel.

16. In a fine-grading machlne, a carriage adapted for travel in a predetermined plane parallel with the planeof the ultimate finegrade, a motor on said carriagefor effecting travel thereof, a shovel element on said carriage adjustable relatively thereto to dispose its cutting edge at any desired elevation relativeto the plane of travel of the carriage, gearing betweenthe motor and the shovel element to reciprocate the cutting edge of the latter during travel of the carriage substantially vertical of the ultimate fine-grade with a movement equal to a fraction of the depth of the earth to be removed.

17. In afine-gradirig machine, a carriage adapted for travel in a predetermined plane parallel withthe plane of the ultimate fine grade,a motor on said carriage for effecting travel thereof, a shovel element on said carriage adjustable relatively thereto to dispose its cutting edge at any desired elevation relative to the plane of travel of the carriage,

gearing between the motor and the shovel element to reciprocate the cutting edge ofthe. latter simultaneously in two directions during travel of the carriage, one of said move ments being longitudinal to the direction of travel of the carriage and the other thereof lateralof said direction of travel.

18. In a fine-grading machine, a carriage adapted for travel in a predetermined plane parallel with the plane of the ultimate finegrade, a motor on said carriage for effecting travel thereof, a'shovel element on said carriage adjustable relatively thereto to dispose its cutting edge at any desired elevation relative to the plane of travel of the carriage. gearing between the motor and the shovel element to reciprocate the cutting edge of the latter simultaneously in a plurality of directions with strokes of a'degree constituting a fraction of the average depth of the earth crust mass to be removed.

19. In a fine-grading machine, a carriage adapted for travel in a predetermined plane parallel with .the plane of the ultimate finegrade, a motor on said carriage for effecting travel thereof, a shovel element on said carriage adjustable relatively thereto to dispose its cutting edge at any desired elevation relative to the plane of travel of the carriage, gearing between the motor and the shovel element to impart to the cutting edge of said shovel a substantially circular movement of a diameter constituting a. fraction of the rate of travel of the carriage per minute.

20. In a fine-grading machine, a carriage adapted for travel in a plane parallel with that of the ultimate fine-grade, a motor on said carriage for eifecting travel thereof,

means on said carriage for eifecting a brealring up into small fragments a thin layer of compact earth immediately above the plane of the ultimate fine-grade to thereby undermine and break up earth masses disposed above saidlayer, and gearing between the motor and said means for actuating the latter relative to said carriage simultaneously with travel of the latter- 21. In a fine-grading machine, a carriage adapted for travel in a plane parallel with that of the ultimate fine-grade, a motor on said carriage for effecting travel thereof, earth cutting means on said carriage adjustable in elevation relative to the plane of travel of the latter for effecting breaking into small fragments a thin layer of com- III) pact earth immediately above'the ultimate I nerade earin between said cut-tin b D O means and said motor for actuating the adapted for travel in a plane parallel with that of the ultimate fine-grade, a downwardly inclined shovel blade supported by and adjustable relatively to the carriage to dispose its cutting edge at any desired elevation relative to the plane of travel of said carriage, a motor on said carriage for eifecting travel thereof, gearing between said motor and said shovel for imparting to the cuttingedge of the latter a limited movement in part at least lateral to the plane of travel of the carriage during travel of the latter, earth removing mechanism disposed to receive loosened earth, and gearing between said mechanism and said shovel blade. 23. In a fine-grading machine, a carriage adapted for travel in-a plane parallel with that of the ultimate fine-grade, a downwardly inclined shovel-blade supported by and adjustable relatively to the carriage to dispose its cutting edge at any desired elevation relative to the plane of travel of said carriage, a motor on said carriage for efiecting travel thereof, gearing between said motor and said shovel blade for imparting o the cutting edge of the latter limited movement in art at least lateral to the plane of travel 0 the carriage during travel of the latter, to thereby effect the breaking up of earth overlying the plane of the ultimate fine-grade, the said broken earth adapted to ascend the shovel blade, earth removing mechanism disposed to receive said earth asit passes over the rear edge of the shovel blade, gearing between said mechanism and said shovel, and gate controlled openings between the ends of said shovel for permitting deposit of loose earth upon the fine-grade rearward of the cutting edge of said shovel blade.-

24. The method of fine-grading a pavement area which consists in maintaining earth cutting means in substantially, the plane of the ultimate fine-grade, eifecting continuous travel of said means, while thus maintained, in a general direction longitudinally of said area, and imparting thereto during said travel, a secondary movement lateral to the general direction of travel.

25. The method of fine-grading a pavement area which consistsv in maintaining earth cutting means in substantially the plane of the ultimate fine-grade, effectingcontinuous travel of said means while thus maintained in a general direction longitudinal to said area, and imparting thereto during said travel, a reciprocatory movement lateral of the general direction of travel.

26. A fine grading machine including a carriage adapted to be'caused to travel in a plane substantially parallel with that of the ultimate fine grade over the area to be fine graded, and a shovelelement mounted on said carriage for movement therewith and for movement relative to said carriage laterally of the plane of travel of the latter during such travel while the shovel edge is maintained substantially continuously in the ultimate fine -grade plane.

27. A fine grading machine including a carriage adapted to be caused to travel in a plane substantially parallel with that of the ultimate fine-grade over the area to be finegraded, and a shovel element mounted on said carriage for movement therewith and for movement relative to said carriage lateral of the plane of travel of the latter during such travel while the shovel edge is maintained substantially continuously in the ultimate fine grade plane, and means operatively associated with said carriage and shovel for limiting said movement of said shovel relative to the carriage.

28. A fine grading machine including a? carriage adapted to be caused to travel in a plane substantially parallel with that of the ultimate fine-grade over the area to be finegraded, and a shovel element mounted on said carriage for movement therewith and for movement relative to said carriage lateral to the plane of travel of the latter during such travel while the shovel edge is maintained substantially continuously in the ultimate fine grade plane and means operatively and adjustably associated with said carriage and shovel for limiting said moVement of said shovel relative to the carriage.

In testimony whereof, I have hereunto set my'hand, this 17th day of November, 1924.

ROBERT D. BAKER. 

